Centerless grinding machine



Filed July 24, 1940 4 Sheets-Sheet 1 jf/ w Get. 28, 1941. A. J. STRONG CENTERLESS GI QINDING MACHINE Filed July 24, 1940 4 Sheets-Sheet 2 Zmoent ar I flr/ w (ZS/m attorneys Get 28, 1941.

A. J." STRONG CENTERLESS GRINDING MACHINE Filed July 24, 1940 4. Sheets-Sheet 3 Oct. 28, 1941. STRONG CENTERLESS GRINDING MACHINE 4 Sheets-Sheet 4 Filed July 24, 1940 (Ittomegs remi s on, 2 ,1941

' j UNITED STATE s PATENT OFFICE 11 Claims.

This invention relates generally to grinding machines. It is an object of the present invention to provide a new and improved so-called centerless grinding machine which will grind internal surfaces of rings in a manner to insure true con- Qgltrlcity of the inner and outer-surfaces of the, r gs.

Another object of the invention is to provide anew and improved grinding machine in which the material to be ground is fed automatically todrive means therefor, which rotates the material relative to a grinding tool. A further object of the invention is to provide for a grinding machine new and improved control means for controlling the operation of feeding work pieces to drive means therefor and controlling operation of the machine, including control of the amount of material removed in grinding operation. v v

Other objects of the invention will become apparent from the following detailed description taken in connection with the drawings in'which:

Fig. 1 is a side view of .th machine partly broken --away and in section, taken along the line I-l of Fig. 3;

2 is a fragmentary top plan machine;

Fig. 3 is a fragmentary end view of the grind ing machine;

Fig. 4 is a fragmentary view of the machine accompanying view ,of the shown partly in vertical section, taken along the line 4-4 of Fig.3;

35 the roller proper by pins 34.

receives a track l5 of the bed H for slidably guiding the upper structure on the bed. Integral with and extending upwardly from the base portion If there is a supporting 'column l6 which, as shown in Fig. 5, is preferably hollow, having side walls I! and I8 and end walls I! and 20. The column end wall I! is provided with 9. preferably dovetailed vertical slideway 2| in which is slidably received and guided, a supporting plate 22.

Externally of the column IS, a pair of vertically spaced hollow bosses 23 are'provided which may be integral with the slide plate 22 and extend transversely of the column 16. A pair of shafts 24 are Journaled respectively in the hollow bosses 23 and have corresponding end portions thereof projecting externally of the bosses beyond or past the column side wall I8 to which end portions are respectively secured a pair of vertically spaced drive members or rollers 25. The opposite ends of the shafts 24 project externally of the bossu, and secured respectively to these ends of the shafts is a pair of pulleys 26 which may be driven via a continuous belt 21 by an electric motor 28, the belt 21 preferably being tightened by an idler pulley 29. The electric' motor 28 is carried by and externally of the a column IS on a suitable platform 30 which may be rigidly secured to the column end wall 20 .by any suitable means.

slde'fianges ll, 32 adapted to receive therewtween a ring member 33 to be ground. As shown in detail in Fig. 7, the side flanges 32 are preferably removable and may be rigidly secured to Adjacent their outer peripheral edges, the flanges are provided in the opposed faces thereof with continuous or circular recesses 35 in which gripping members,

preferably rubber rings-38, are inserted, which rubber rings are preferably stiffened by circular backing rings 31 secured thereto. when a work piece or metallic ring 33, such as a bearing race, is positioned between the flanges 31,}! ofthe rollers 2 5, the rubber gripping rings thereof are slightly compressed to increase the cooperating frictional forces for rotating the ring a, during erence, the grinding machine shown includes a substantially rectangular base I. having an upper surface or bed II on which an upper, supporting structure or carriage I2 is supported for sliding movement crosswise or transversely of the base.

which rotation the ring is ground either internally or externally, or both, by a suitable grinding wheel 34. It will be understood that the work against the opposite surfaces of the ring.

, as is more clearly shown in Fig. 1, a horizontal "guideway 381s provided'in the column sidewall Each of the rollers 25 isprovided withspace'd piece or ring 33 is driven or rotated solely by reason of the frictional drive of the rollers 28 carrier or holder member 39 for feeding and holdportion including a pair of'spaced, rigid arms or.

projections 43 between which a socket is provided for the rings 33. In Fig. l, for example, the carrier member 39 is shown holding a ring 33 in position to be rotated by the rollers 25 but when the member 39 is drawn back to what may be termed its starting position, the space between the arms 43 is immediately below the outlet of the magazine or in position to receive the next ring 33. It will be seen that the yolk arms 43 and the supporting member 39 provide bearing surfaces which permit rotation of a ring 33 positioned in the yoke but prevent bodily movement of the ring during the grinding operation, and since the ring is gripped on opposite sides thereof by the drive rollers 25, concentricity of the inner and outer peripheries is assured after the grinding operation is completed. Preferably the opposed faces of the yolk arms 43and the upper surface of the supporting member 4| are provided with hardenedinserts 45 to reduce wear.

The member 39 is connected by a connecting rod 46 to a piston 41 in a hydraulic cylinder 48, which may be rigidly secured to the motor platform 30 by a suitable bracket 49. This hydraulic ,power means .15 controlled by a valve 58 which is connected to opposite ends of the cylinder 48 by conduits Any suitable type of valve operable to establish communication alternately between a source of fluid pressure and opposite ends of the cylinder may be employed to reciprocate the ring carrier and holder 39. In the present instance, the valve 50 is actuated in opposite directions by a pair of oppositely acting solenoids 52 and 53, the plungers or cores 54 and 55 of which are connected to a common operating arm 56 of the valve member, as at 51. In Figs. 8 and 9, the valve member 51 has been moved by the solenoid 52 to the position which will permit fluid to escape from the cylinder 48 via the conduit 5la and will permit the fluid under pressure to enter the cylinder 48 via the conduit 5| to act against the piston 41 and move it to the left. In Figs. and 11, the piston has been moved to the left and the carrier 39 has positioned the ring 48 carried thereby between the flanges 3|, 32 of the drive rollers 25, movement of the carrier to the left being limited by engagement of the piston 41 with the left end wall of the cylinder 48. Whenthe other solenoid, or solenoid 53 is energized, it actuates the valve member 50, which reverses the application of fluid pressure on the piston 41, causing the ring or work piece carrier 39 to be drawn back to its starting position shown in Figs. 8 and 9.

As previously mentioned, the upper supporting structure l2 on which the carrier is mounted is slidable on the base l0 transversely thereof. This provides for positioning the work piece or ring 33 held by the carrier39 over the grinding wheel 34 which then extends into the ring, the axis of rotation of the grinding wheel being parallel with the axis of the ring. Preferably, the transverse or reciprocal movement of the upper structure I2 is accomplished by a hydraulically operated piston 58 in a cylinder 59 which may be mounted rigidly on the base llbeneath the bed H thereof. Rigidly secured'to thepiston 58 is one end of a push rod 60, of which the other end is rigidly secured to 9. depending integral boss 6| of the upper structure base l3, see Fig. l, 8 or 10.

Supply of fluid pressure to opposite sides of the piston 58 is controlled by a valve 62 having a rotatable valve member 63 controlling the ports of the valve. As shown, the valve 62 is the same as the previously described valve Bland may be of any suitable type operable to direct the fluid pressure against one end of the piston 58 and later against the other end of the piston 58 to reciprocate the piston. The ports of the valve 62, which are both inlet and outlet ports, are connected respectively to opposite ends of the cylinder 59 by suitable conduits 64 and 64a. A solenoid 65 is provided to rotate the valve member 63 in a direction to establish communication between the source of fluid'pressure and the left end of the cylinder 59, as seen in Figs. 8 and 10, the reciprocal core 66 of the solenoid 65 being connected by a link 61 to-an operating lever arm 68 of the valve member 63. A helical coil spring 10 may be provided and have one end attached to the operating valve arm 68 to rotate the valve member 63 in the opposite direction upon deenergization of the solenoid 65; When the solenoid 65 rotates the valve member 63 to establish communication between the source of fluid pressure and the leftend of the cylinder 58, the upper structure I2 is moved by the fluid pressure toward the grinding wheel 34 to position the work piece or ring 33 in the carrier 39 such that the work piece surrounds the grinding wheel 34. After the grinding operation is completed, the solenoid 65 is deenergized, which permits the spring 19 to rotate the valve member 63 to a position establishing communication between the source of fluid pressure and the right hand end of the cylinder 59 with the result that the upper structure I2 is moved away from the grinding wheel 34. For a reason which will be hereinafter explained, it is desired that the solenoid, upon being energized, has'a delayed action, and to this end, the solenoid is provided with a dash pct 12, although other types of solenoids having other means for providing delayed actions may be employed.

The grinding wheel 34 is secured to and adjacent one end of a rotatable horizontal shaft 12 which isjournaled in a standard 13 and may be driven by an electric motor 13a which is also mounted on the standard 13. The, standard 13 is mounted on a second standard 14 in a dovetailed slideway 14a for adjustment movement toward and away from the work piece or ring 33 held by the carrier39. Depending into the standard 14, an integral boss 15 of the upper standard 13 is provided-with a threaded bore to receive a rotatable screw 16 which may be rotated by a hand wheel 11 to slide the upper standard 13 on the lower standard 14 to adjust the position of the grinding wheel relatively to the ring 33. The lower standard 14 is slidably mounted in a dovetailed slideway 18, Figs. 3 and 4, provided in the top or bed of a lower standard 19 which straddles the upper base l3 and is rigidly secured by bolts 89 to the lower or main base I of the machine. As shown, the standard 14 is arranged to move longitudinally of the ring carrier member 39 or to move transversely of the axis of the ring 33, this movement being provided to bring the periphery of the grinding Whfl'i up .vided with a threaded bore to receive a rotatable screw 82 for sliding the upper standard I4 on the lower o'r flxed standard "I9.

The power element piston 84 is integral'with an upwardly extending push rod 86 which is pivoted at its upper end to a lever 81, secured on and to the outer end of the screw 82, thus operatively connecting the screw to the power element 83. A two-way valve 88 is provided for controlling the power-element 83 and is connected byconduits 89 and 90 to the power element cylinder 85 at opposite ends of the piston 84, the valve in turn being connected by suitable conduits to a source of fluid pressure.- A sole-' noid 9| is provided to actuate the valve 88 which is provided with an operating arm 92 connected to the solenoid core 93 by a link 94. The solenoid 9| may be rigidly mounted on the lower or iixed standard I9 by-a bracket 95. A hand wheel 96 for the screw 82 may be provided for-initially adjusting the position of. the standard I4 and consequently the position of the grinding wheel a 34 prior to operation thereof by the power element 83. A helical coil spring 91, connected to the valve operating arm 92, may be provided to operate the valve in the opposite direction or to return it to the position from which it is moved by the solenoid 9I.

A pair of spacedswltches vided and are actuated in accordance with the movement of theupper structure toward and away from the grindingwheel by the power element 59. The switches 98 and 99 may be mounted respectively on a pair of brackets I00, secured to and depending from the underside of the main base I0, see Figs. 3, 4-and 10. The switch 98 comprises, in general, a contact member IOI cooperable with a contact member I02 carried by and adjacent one or the free end of a flexible switch blade J03. Similarly, the switch 93 comprises, in general, a contact member I04 cooperable with a contactmember I05 which is carried by a flexible blade I06. A switch I01 is mounted on one end of the support H and is actuated by the carrier 39, the switch I0I comprising a flexible blade I08 carrying adjacent the free end thereof a-contact member I09.- Cooperable with the'contact member I09 there is a flexible blade-like contact member I II which is .arranged in spaced relation to the'blade I08.

The two flexible blades I08 and I III are secured to an'eiectric insulating base I II which is rigidly secured to the end of thesupport 4!. The'insulator III extends upwardly above the support H and is provided with an aperture therethrough ..in which a pin Illa is disposedhaving one end engaging the flexible blade IIO, the other end of the pin being engageable by the adjacent end,

of the carrier member 39. The-carrier member 39 also actuates a second switch II2 which is mounted on an electric insulating plate II3 electric insulation H0. 0n opposite sides thereof the blades H4 and II! respectively are pro- 98' and '99 are provided with contact members I" and III which respectively cooperate with contact members II! ,ing lug I26 on the carrier 39.

Another switch, designated in general by the numeral I21, is provided and functions to stop the machine in the event that the magazine 42 becomes empty of the work pieces or rings 33. To this end, the switch I2'l is mounted on the underside of the magazine 42 and is held in closed circuit position solely by the weight of one of the rings 33 in the magazine. Electric insulating material I28 is secured to the underside of the magazine 42 and secured to the insulating material there is a horizontal metallic plate I30 to which aconta'ct member I3I is secured. A flexible blade I32 is secured at one end thereof to the insulator I28 and the blade I32 carries adjacent the free end thereof a contact member I'33which is cooperable with the contact member I3I. Disposed in an opening in the bottom of the magazine 42 there is a lever I on which the rings 33 rest, which lever is pivoted adjacent one end thereof to the magazine 42. Ad-

' jacent its free end the lever I35 is held up by switch I done a leaf spring I35a which is secured to the underside of the magazine, and intermediate its ends, the'lever I35 is provided with a downwardly directed extension I36 which engages the blade I32 to hold the blade down and the switch contacts together. Another switch I38 isprovided and controls or determines the amount of material removed fromeach of the ring members 33. This I38 is carried by the carrier in the yoke of which is'provided a transverse hole in which a tubular casing I39 for the switch is slidably.

received and guided.- Pivoted to and within the casing I39 there is a switch arm I which is cooperable with a contact member I42 which is secured to andwithin'the casing. .One endof the operating arm I4'I projects externally of the casing I40 for engagement with the inner surface of the rings 33when'the ring is positioned ready to be ground, the ring thus holding the switch closed. when the switch is closed, the arm I engages andtensions a leaf spring I42a which then acts to open the switch and becomes effective after the desired amount of material has been removed from the ring, V

The closed end of the casing I40 is provided with an extension which carries a pin I" which serves asa cam follower and engages in a cam slot I44 provided inapiate like cam member I44a. The cam member is fixed relatively to the work carrier 39 and the slot I44 is provided with an onset to retain reciprocal movement of the switch I38 as a unit. It will be seen that as the carrier moves to the left from the po'sitionshown in Fig. 9 to.the position shown inFig. '11, the w switch I38 is moved in toward the carrier until the switch operating arm extends into the ring 33 in contact with the inner surface thereof. The switch I38 is provided with terminals, I46, I44,-

of which the terminal I48 is connected by a lead lead wire I56 to the switch contact IIII.

wire I41 to the blade of the switch 98, and the other terminal I46 is connected by a lead wire I48 to the blade I32 of the switch I21, the switch contact member I3I being connected to one of the main terminals by a lead wire I50. A lead wire'I5I connects the contact member I09 of the switch I01 to the lead wire I41 and a lead wire I52 connects the switch blade IIO to one terminal of the solenoid 65. From the other terminal of the-solenoid 65, a lead wire I53 is connected to the second of the main lead wires I54. A lead wire I55 connects one terminal of the solenoid 9| to the main lead wire I54, the other terminal of the solenoid being connected by a The main lead wire I54 is connected to one terminal of the solenoid 53 and the other terminal of the solenoid is connected by a'lead wire I51 to the blade I01 of the switch 99. Similarly, the solenoid 52 has one terminal thereof connected by a lead wire I58 to the main lead wire I54 and its other terminal is connected by a lead wire I59 to the switch contact member I20. From the terminal of the switch blade II5, a lead wire I60 connects to the lead wire I48, and from the switch blade II 4 a lead wire I6I connects to the terminal of the switch contact member I04, the

wire I60 being connected by a lead wire I62 to the terminal of the contact member II9. It will be noted that the solenoids 65 and BI are in par allel circuit. The solenoid 65 is'connected in series circuit with the switch I01 and the solenoid 9| is in series circuit with the switch 98 and the switch I01. Also the switch 3 is in series circuit with each of the solenoids 52 and 53 and switches I21 and I38 are in series circuit with each other and with the switches I01 and 99 and with the solenoids 52 and 53.

Referring now to the magazine 42, a bell crank I lever I66 is pivoted to one side of the magazine,

adjacent the outlet thereof, and has a depending arm to the lower end of which is secured a laterally extending pin I61 which engages the ring 33 at the magazine outlet to prevent its discharge therefrom until the lever is pivoted in a clockwise direction, facing Fig. 1. The other arm of the bell crank lever I66 is connected by a link I68 to one end of a lever 069. The lever I69 is pivoted intermediate its ends to a bracket I10 which is rigidly secured to the magazine 42. Be-

tween the lever fulcrum and the link I68 the lever is provided with a pin I1I to which is attached one end of a coil spring I12, the other end of the spring being anchored to the magazine. The spring I12 acts to pivot the lever I69 in a clockwise direction and through the link I68 to pivot the bell crank lever I66 in a counter-clockwise direction which movement is limited by a stop pin I13, secured to the magazine 42. A pawl I14 is pivoted to the carrier 39 adjacent the rear end thereof and is held against a stop member I15 by a helical coil spring I16. When the car-' rier is returned to its starting position, the pawl engages a laterally extending pin I11 carried by the lower, free end of the lever and pivots to pass by the pin. When the carrier member 39 again moves toward the drive rollers 25, the pawl I14 engages the pin I11 and pivots the lever I69 in a clockwise direction which moves the lower arm of the bell crank lever I66 away from the ring 33 at the magazine opening thus permitting the ring 33 to descend by gravity onto the support 4I bet-ween the arms 43 of the carrier yoke.

A lever I18 is pivoted intermediate its ends by a pin I 19 to the top of the carrier member lever I18 is pivoted a pair of plate-like members "M which are adapted to engage a finished ring 33 and eject it from the yoke or from between the arms 43 thereof when the lever I18 is pivoted in a counter-clockwise direction facing Fig. 6. The ejected rings 33 may fall into a second magazine or conveyor I80. A pair of tensioned springs I8I wrapped around the pin I19 have ends thereof abutting a'pin I82 on the carrier 39 and the other-ends thereofabutting.

a pin I83 on the lever I18, the springs I8I acting to pivot the lever in a direction to move the plate member I 18a back between the yoke arm 43, see Fig. 6. The lever I18 is swung in the opposite direction by a cam member I84 having an inclined cam surface I85 engageable by a pin I86 carried by a relatively short arm I81 of the lever I18. A guide member I88 is rigidly secured to the magazine 42 and is arranged to guide a ring in the yoke of the carrier 39 between the flanges of the rollers 25.

In general the machine operates as follows: The carrier 39 receives a ring 33 from the magazine 42 and moves the ring to be ground to the left, facing Figs. 9 and 10, such movement being limited by engagement of the power element piston 41 with the end of its cylinder. This positions the ring '33 between the flanges of the drive. rollers 25. When the ,ring is moved to this position, the entire upper structure moves transversely of its base to position the ring 33 over the grinding wheel 34 and then the sup-g ring wheel 34 against the inner surface of the ring 33. After the grinding operation is completed, the grinding wheel is first moved away from the inner surface of the ring 33 and then the upper structure moves to withdraw the ring from the grinding wheel 34, after which the carrier 39 moves back toward its starting position.

In Fig. 8, the parts of the machine are shown in the-positions they will assume at the start of the operation. It will be noted that the lower blade II5 of the switch H3 is being held in contact with the contact member I3I by the lever I25, which is pivoted and releasably heldby the extension I26 of the carrier 39. This completes the following circuit to the solenoid 52: From the main lead wire. I50 through the switch I21 which is held closed by the rings 33 in the magazine 42, lead wires I48, I60, switch blade 'II5,

contact ,I20, lead wire I59, solenoid 52, and lead wire I58 to the other main lead wire I54. When the solenoid 52 is energized, it acts to move and hold the valve member 51 in the position shown in Fig. 9, in which position of the valve fluid pressure is acting to move the carrier 39 to the left. Upon movement of the carrier 39 to the left, the pawl I14 on the ring carrier 39 engages the pin I11 of the lever I69 and pivots the lever in a clockwise direction, Fig. l, which through the link I68 pivotsthe lever I66 in a clockwise direction thus moving the stop pin I61 to permit the ring 33 at the magazine opening to descend onto the support -4I between the arms 43 of the carrier 39. The'carrier 39 moves the ring 33 to the left until thepiston 41 is stopped by its engagement with the cylinder end wall. During this movement; of the carrier 39, the switch I38 carried thereby is moved toward the ring 33 by reason of the follower riding in the H3, is in open circuit position:

' the circuits of the solenoids 65 and SI.

operating arm'l4l engages the inner surface of the ring to be ground. As the carrier 99 moves. to the left, the switch blades 4 and 5 are released thereby, and, flexing upwardly, the upper blade II4 engages its contact member I I9. This, however, does not complete a circuit for the reason that switch 99, in series with switch Just prior to the stopping. of the carrier movement, the carrier 39 engages the pin Illa and closes the switch. 101 which closes the following circuit:

From the main lead wire I54 through the solenoid lead wire I52, switchblade IIII, contact I89, switch I38, lead wire I48, switch I2'I to the other main lead wire I58. When the solenoid 65 is energized it moves the valve member v 88 to the position shown in 10, which permitsthe fluid pressure to act on the piston 58 and move the piston to the right whichthrough the rod 68 moves the entire upper structure l2 adjacent the end oi! the piston rod 50. When.

the switch 98 is closed, the circuit of the'solenoid 9| is closed, which circuit is as follows: From the main lead wire I54 through lead wire I55, solenoid 9|, lead wire I56, switch 98, lead wire I41, switch I38, lead wire I48, switch I21, to the other main line I59. When the solenoid 9| is energized, it actuates the valve member 51, which then directs the fluid pressure against the upper end of the piston 84. The piston 84 then moves downwardly, and, operating the lever 81, moves the upper grinding wheel support 19 longitudinally of the carrier 99 to position the grinding wheel against the inner surface of the While I have shown and described my invention in detail, it is to be understood that the same is to be limited only by the appended claims for many changes may be made withoutdeparting from the spirit and scope of theinvention.

WhatIclaimis:

1. In a grinding machine having a grinding means for grinding a surface of a ring member, supporting means for engagement by the outer periphery of the ring membenaholdelillr hold- 8 ing the ring member in aibsltion tor the grinding operation, and a pair of spaced rotatabledrive members each having spaced outer peripheral flanges between which the opposite sides of the ring member are engaged to rotate the ring member on its outer periphery'on said supporting means. r

2. In a grinding machine having a' grinding wheel for grindi'nga ring member, J supporting means for engagement by the outer periphery of the ring member, a pair of spaced drive members having flanges for engaging opposite sides oi and rotating the ring member, a reciprocal holder for the ring member, said holder being operable to'position the ring member between-the flanges of said drive members and to withdraw the ring member upon completion oi the grinding operation, and means controlling; reciprocation of said holder. r

3. In a grinding machine having a' grinding wheel for grinding a ring member, supporting ber during the grinding operation, a reciprocah holder operable to position the ring member between the flanges of said drive members and to ring 49. After a predetermined desired amount of material has been removed from the inner surface of the ring 33, the switch I38 will open This deenergizes the solenoids, thus permitting their springs I9 and 91 to actuate respectively the valves 62 and 88, but, due to the delayed action or the solenoid 65 because oi! the dash pot I2, the spring 91 actuates the valve 98 before valve 82 is actuated. Y The spring 91 rotates the valve member to the position shown in Fig. 8, in which position the fluid pressure acts against the underside oi the piston 84 which moves the piston upwardly to pivot lever 81 which rotates screw 82 to move the grinding wheel 84 away from the inner surface of the ring 40. The spring 18 now acts to move the valve member 63 from the position shown in Fig. 10 to the position shown in Fig. 6, which reverses the direction of,

fluid flow to the power element cylinder 59. 'The fluid pressure now acm against the right end of the piston 58 and moves the piston to the leit which permits the switch 98 to open. This 7 moves the entire upper structure I! away from the grinding wheel 94, and during this mOVe-.' ment the depending abutment carried by the boss 8| engages the flexible switch blade Illi. making contact between the contact members ll4 and I85. This closes the circuit 01 the sole withdraw' the ring member upon completion of the'grinding operation, said holder being movabl laterally toward the grinding wheel, and means controlling said lateral'movement and actuated by reciprocal movement of said holder.

4. In a grinding machine having a grinding wheel for grinding a ring member, a movable carriage, supporting means on said carriage for engagement by the periphery oi the ring member, a pair of spaced drive members on said carriage, said drive members having spaced outer peripheral flanges to receive the ring member .therebetween, said flanges engaging opposite sides of the ring member ,ior irictionally rotating the'ring member during the grinding operation,- a holder for the ring member and carried by said carriage, said holder being movable in one direction to position the ring member between the flanges-of said drive members, means controlling reciprocation of said holder, said carriage being movable'transversely to the direction ofmovement of said holder for moving the ring member toward the grindingwheel and means controlling movement of said carriage and operable in accordance'with movement. of saidholder.

5. In a grinding machine having a grinding to rotate the ringmembers during the grinding operation, a container for a plurality of the ring members and having'an outlet, a holder member. 7 lil, blade. I30 to the other main lead wire I50. on said carriage for one of the ring members neath the outlet of said container to receive a ring member, said holder being movable in the opposite direction to position the ring members carried thereby between the flanges of said drive members, said carriage being movable transversely to the movement of said holder to move the ring member toward the grinding wheel, means controlling movement or said carriage and ac-' tuated by said holder, and means controlling the outlet of saidcontainer and actuated by said holder.

6. In a grinding machine having a grinding wheel for grinding a ring member, a movable carriage, supporting means on said carriage for engagement by the outer periphery of the ring member, a pair of spaced drive members on said carriage, said drive members having spaced outer peripheral flanges to receive the ring member therebetween and engage opposite sides thereof to rotate the ring members during the grinding operation, a container for a plurality of the ring members and having an outlet, a holder member 2,260,843 I and movable in one direction to a position besaid lateral movement and actuated by reciprocal movement of said holder.

9. In a grinding machine having a grinding wheel for grinding a ring member, a movable carriage, supporting means on said carriage for engagement by the periphery of the ring member, a drive member on said carriage, said drive membe! having spaced outer peripheral flanges to receive the ring member therebetween, said flanges engaging opposite sides of the ringme'mber for and operable in accordance with movement of on said carriage for one of the ring members and movable in one direction to a position beneath the outlet of said container to receive a ring member, said holder being movable in the opposite direction to position the ring members carried thereby between the flanges of said drive members, said carriage being movable transversely to the movement of said holder to, move the ring member toward the grinding wheel, means controlling movement of said carriage and actuated by said holder, and means controlling the outlet of said container and actuated by said holder and means fordischarging the ground ring member from said holder end actuated by said holder.

10. In a grinding machine having a grinding wheel for grinding a ring member, a movable carriage, supporting means on said carriage for engagement by the outer periphery of the ring member, a drive member on said carriage, said movement of said holder toward said first-named position.

7. In a grinding machine having a grinding wheel for grinding a ring member, supporting means for engagement by the outer periphery of the ring member, a drive member having flanges for engaging opposite sides of'and rotating the ring member, a reciprocal holder for the ring member, said holder being operable to position the ring member between the flanges of said drive I member and to withdraw the ring member upon completion of the grinding operation, and means controlling reciprocation of said holder.

8. In a grinding machine having a grinding wheel -for grinding a'ring member, supporting means for engagement by the outer periphery of the ring member, a drive member having spaced outer peripheral flanges to engage opposite sides of and rotate the ring member during the grinding operation, a reciprocal holder operable to position the ring member between the flanges of said drive member and to withdraw the ring member upon completion of the grinding operation, said holder being movable laterally to-' ward the grinding wheel, and means controlling drive member having spaced outer peripheral flanges to receive the ring member therebetween and engage opposite sides thereof to rotate the ring members during the grinding operation, a container for a plurality of the ring members and having an outlet, a holder member on said carriage for one of the ring members and movable in one direction to a position beneath the outlet of said container to receive a ring member, said holder being movable in the opposite direction to position the ring members carried thereby between the flanges of said drive member, said carriage being movable transversely to the movement of said holder to move the ring member toward the grinding wheel, means controlling movernent of said carriage and actuated by said holder, and means controlling the outlet of said container and actuated by said holder and means for discharging the ground ring member from said holder end actuated by movement of said holder toward said first-named position.

11. In a grinding machine having a grinding wheel for grinding a work piece, drive means for rotating the work piece during the grinding operation, a reciprocal holder for the work piece, said holder being movable in one direction to position the workpiece in driving relation with said drive means and movable in the opposite direction to withdraw the work piece, switch means controlling reciprocation of said holder and actuated thereby, said holder also being movable laterally to-move the work piece toward said grinding wheel, and switch means controlling lateral 

